检测前一天，工作负责人应确认检测工器具是否（）。
A.合格
B.完好
C.齐备
D.在校验有效期内
参考答案：B, C, D
I'm so glad to see you back, Lucy. How long _____ at your grandma's?[ ]
A. had you stayed
B. did you stay
C. have you stayed
D. do you stay
属于天然甜味剂的是
A．糖精钠B．木糖醇C．安赛蜜D．甜蜜素E．阿斯巴甜
